Effect of frequent interruptions of sedentary time on nutrient metabolism in sedentary overweight male and female adults

Nathan P de Jong (1) , Corey A Rynders (2) , David A Goldstrohm , Zhaoxing Pan , Andrew H Lange (1) , Carlos Mendez (1) , Edward L Melanson , Daniel H Bessesen (3, 1) , Audrey Bergouignan (1, 4)

1 Division of Endocrinology, Metabolism and Diabetes, Department of Medicine
2 University of Colorado [Denver]
3 Denver Health Medical Center
4 DEPE-IPHC - Département Ecologie, Physiologie et Ethologie

OBJECTIVE: This study compared 24-h nutrient oxidation responses between a sedentary condition (SED) and a condition where short 5-min bouts of moderate-intensity physical activity were performed hourly for 9 consecutive hours over 4-d (MICRO). To determine whether any shifts in fuel use were due solely to increases in energy expenditure we also studied a condition consisting of a single isoenergetic 45-min bout of moderate-intensity exercise (ONE). METHODS: Twenty sedentary overweight or obese adults (10M/10F; 32.4+/-6.3 years; BMI, 30.6+/-2.9kg/m(2)) completed all three conditions (MICRO, SED, and ONE) in a randomized order. Each condition consisted of a 3 d free-living run-in followed by a 24-h stay in a whole-room calorimeter to measure total energy expenditure (TEE) and substrate utilization. Dietary fat oxidation was also assessed during the chamber stay by administering a [1-(13)C] oleic acid tracer at breakfast. Energy intake was matched across conditions. RESULTS: Both MICRO and ONE increased TEE relative to SED resulting in a negative energy balance. HOMA-IR improved in both activity conditions. MICRO increased 24-h carbohydrate oxidation compared to both ONE and SED (p<0.01 for both). ONE was associated with higher 24-h total fat oxidation compared to SED, and higher 24-h dietary fat oxidation compared to both SED and MICRO. Differences in substrate oxidation remained significant after adjusting for energy balance. CONCLUSION: In overweight and obese men and women, breaking up sitting time increased reliance upon carbohydrate as fuel over 24-h while a single energy-matched continuous bout of exercise preferentially relies upon fat over 24-h.

Domaines: Sciences de l'environnement

Nathan P de Jong, Corey A Rynders, David A Goldstrohm, Zhaoxing Pan, Andrew H Lange, et al.. Effect of frequent interruptions of sedentary time on nutrient metabolism in sedentary overweight male and female adults. Journal of Applied Physiology, 2019, 126 (4), pp.984-992. ⟨10.1152/japplphysiol.00632.2018⟩. ⟨hal-02108332⟩